1. Field of the Investigation
This invention relates to improvements in locks and more particularly to a lock suitable for the locking of a sliding closure such as a sliding door.
2. Background Information
Locks commonly used for latching-closed a sliding closure such as a sliding door have a lock beak which hooks into an opening in a latch plate or strike. Forced entry through the door is possible since the door usually can be lifted sufficiently to release the beak from the strike. To try and overcome this possibility, it is known to have a pair of locking beaks which lock in opposite directions and thereby resist any forced entry caused by lifting the door. However, it is still possible to apply force to the door in such a manner as to drive the beaks out of the locking position and thereby permit the door to be opened.
A problem which can also arise with locks for sliding doors is that the locking beak can be located in the locking position when the door is not in the fully closed and therefore lockable position. Thus, if the door is slammed shut with the beaks already in the locking position, damage to the beaks and/or lock mechanism can occur. Furthermore, damage to the strike can possibly also take place as the extended beak hits the strike.